In surfactant flooding for enhanced oil recovery, adsorption of surfactants on the porous media of an oil reservoir is a major concern. It weakens the efficacy of the injected surfactant in reducing oil–water interfacial tension (IFT) and makes the oil recovery process uneconomical. Colloidal silica nanoparticles were found to adsorb at a lower rate than surfactant in porous media because of their charge density and high surface area. Silica nanoparticle surfaces with a negative surface charge are expected to adsorb onto the same active sites in the reservoir as anionic surfactant molecules used in enhanced oil recovery (EOR) applications. Experiments conducted in sandpack demonstrated that pre-treatment of the sandpack with silica nanoparticles at 80°C reduced surfactant adsorption by a factor of three when using artificial seawater as the injection fluid.